Artificial promiscuous t helper cell epitopes as immune stimulators for synthetic peptide immunogens

Abstract

The present invention is directed to novel promiscuous and artificial T helper cell epitopes (Th epitopes) designed to provide optimum immunogenicity of a target antigenic site. The target antigenic site can include a B cell epitope, a CTL epitope, a peptide hapten, a non-peptide hapten, or any immunologically reactive analogue thereof. The disclosed Th epitopes, when covalently linked to a target antigenic site in a peptide immunogen construct, elicit a strong B cell antibody response or an effector T cell response to the target antigenic site. The Th epitopes are immunosilent on their own, i.e., little, if any, of the antibodies generated by the peptide immunogen constructs will be directed towards the Th epitope, thus allowing a very focused immune response directed to the targeted antigenic site. The promiscuous artificial Th epitopes provide effective and safe peptide immunogens that do not generate inflammatory, anti-self, cell-mediated immune responses following administration.

1 . A promiscuous artificial T helper cell (Th) epitope selected from the group consisting of SEQ ID NOs: 32-52. 
     
     
         2 . A peptide immunogen construct represented by the following formulae:
   (A) n -(Target antigenic site)-(B) o -(Th) m -(A) n -X     or     (A) n -(Th) m -(B) o -(Target antigenic site)-(A) n -X     or     (A) n -(Th) m -(B) o -(Target antigenic site)-(B) o -(Th) m -(A) n -X     or     {(A) n -(Th)p-(B) o -(Target antigenic site)-(B) o -(Th) p -(A) n -X} m      
       wherein:
 each A is independently an amino acid; 
 each B is independently a heterologous spacer; 
 each Th is independently a promiscuous artificial Th epitope selected from the group consisting of SEQ ID NOs: 1-52; 
 the Target antigenic site is a B cell epitope from a foreign-antigen protein, a self-antigen protein, a CTL epitope, a Tumor-Associated Carbohydrate Antigen (TACA), a B cell epitope from a neoantigen, a small molecule drug, or an immunologically reactive analogue thereof; 
 X is an amino acid, α-COOH, or α-CONH 2 ; 
 n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; 
 m is 1, 2, 3, or 4; and 
 o is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and 
 p is 0, 1, 2, 3, or 4. 
 
     
     
         3 . (canceled) 
     
     
         4 . The peptide immunogen construct of  claim 2 , wherein the target antigenic site is a B cell epitope from a self-antigen protein selected from the group consisting of:
 (a) an Aβ peptide having the amino acid sequence of SEQ ID NO: 56, 57, 58, 59, or 60;   (b) an alpha-Syn peptide having the amino acid sequence of SEQ ID NO: 61;   (c) an IgE EMPD peptide having the amino acid sequence of SEQ ID NO: 62;   (d) a Tau peptide having the amino acid sequence of SEQ ID NO: 63, 69, 70, or 71;   (e) an IL-31 peptide having the amino acid sequence of SEQ ID NO: 64 or 72; and   (f) an IL-6 peptide having the amino acid sequence of SEQ ID NO: 145.   
     
     
         5 . The peptide immunogen construct of  claim 2 , wherein the heterologous spacer of component B is selected from the group consisting of an amino acid, Lys-, Gly-, Lys-Lys-Lys-, (α, ε-N)Lys, ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 53), Lys-Lys-Lys-εNLys (SEQ ID NO: 54), Gly-Gly, Pro-Pro-Xaa-Pro-Xaa-Pro (SEQ ID NO: 55), and any combination thereof. 
     
     
         6 .- 11 . (canceled) 
     
     
         12 . The peptide immunogen construct of  claim 2 , wherein the target antigenic site is a CTL epitope having an amino acid sequence selected from the group consisting of SEQ ID NOs: 76-144. 
     
     
         13 .- 17 . (canceled) 
     
     
         18 . The peptide immunogen construct of  claim 2 , wherein the target antigenic site is a TACA selected from the group consisting of GD3, GD2, Globo-H, GM2, Fucosyl GM1, GM2, PSA, Le y , Le x , SLe x , SLe a , Tn, TF, and STn. 
     
     
         19 . The peptide immunogen construct of  claim 2 , wherein the target antigenic site is a B cell epitope from a neoantigen selected from the group consisting of SEQ ID NOs: 73-75. 
     
     
         20 . The peptide immunogen construct of  claim 2 , wherein the target antigenic site is a small molecule drug. 
     
     
         21 .- 22 . (canceled) 
     
     
         23 . A pharmaceutical composition comprising the peptide immunogen construct according to  claim 2 . 
     
     
         24 . A method of preventing and/or treating a disease, condition, or ailment in a subject comprising administering a pharmaceutically affective amount of the pharmaceutical composition of  claim 23  to the subject. 
     
     
         25 . The method according to  claim 24 , wherein the disease, condition, or ailment is HIV and wherein the target antigenic site is a CTL epitope from HIV selected from the group consisting of SEQ ID NOs: 76-82. 
     
     
         26 . The method according to  claim 24 , wherein the disease, condition, or ailment is HSV and wherein the target antigenic site is a CTL epitope from HSV selected from the group consisting of SEQ ID NOs: 83-106. 
     
     
         27 . The method according to  claim 24 , wherein the disease, condition, or ailment is FMDV and wherein the target antigenic site is a CTL epitope from FMDV selected from the group consisting of SEQ ID NOs: 107-123. 
     
     
         28 . The method according to  claim 24 , wherein the disease, condition, or ailment is PRRSV and wherein the target antigenic site is a CTL epitope from PRRSV selected from the group consisting of SEQ ID NOs: 124-142. 
     
     
         29 . The method according to  claim 24 , wherein the disease, condition, or ailment is CSFV and wherein the target antigenic site is a CTL epitope from CSFV selected from the group consisting of SEQ ID NOs: 143-144. 
     
     
         30 . (canceled) 
     
     
         31 . The method according to  claim 24 , wherein the disease, condition, or ailment is cancer and wherein the target antigenic site is a TACA selected from the group consisting of GD3, GD2, Globo-H, GM2, Fucosyl GM1, GM2, PSA, Ley, Lex, SLex, SLea, Tn, TF, and STn. 
     
     
         32 . The method according to  claim 24 , wherein the disease, condition, or ailment is cancer and wherein the target antigenic site is a B cell epitope from a neoantigen selected from the group consisting of SEQ ID NOs: 73-75. 
     
     
         33 . A method for tailoring an immune response in a subject comprising:
 (a) preparing more than one peptide immunogen construct according to  claim 2 , wherein the Target antigenic site remains constant and the Th epitope is different on each peptide immunogen construct;   (b) preparing more than one pharmaceutical composition, each of which comprises one of the peptide immunogen constructs prepared in (a) and a pharmaceutically acceptable adjuvant or carrier;   (c) administering each of the pharmaceutical compositions prepared in (b) to different subjects;   (d) monitoring the immune response in each of the subjects; and   (e) selecting the pharmaceutical composition that produces a desired immune response.   
     
     
         34 . The method according to  claim 33 , wherein the pharmaceutically acceptable adjuvant or carrier in each of the pharmaceutical compositions is the same. 
     
     
         35 . The method according to  claim 33 , wherein the pharmaceutically acceptable adjuvant or carrier in each of the pharmaceutical compositions is different.